Energy Department Updates National Solar Thermal Test Facility

The molten salt test loop is the only test facility in the country that can provide real power plant conditions and collect data about the interactions of pressure, temperature, and flow rates.Credit: Randy Montoya, Sandia

The Energy Department's National Solar Thermal Test Facility (NSTTF), operated by the Department's Sandia National Laboratories, was recently overhauled. The $17.8 million upgrade to the NSTTF added state-of-the-art test capabilities. The resulting research conducted at the facility is expected to lead to more solar power use on the electric grid.

The American Recovery and Reinvestment Act funded the nine-part project consisting of new additions and upgrades to the test center, much of which had not been updated since it was built in 1976. The improvements include adding a new $10 million molten salt test loop, an optical methods laboratory and other critical testing capabilities, and upgrading the parabolic trough test platform. It also included a $3.8 million investment to replace the 218 original heliostat mirrors aimed at the Solar Tower, a key improvement because glass and reflective technology have change significantly in the past three decades.

The facility uses concentrating solar power (CSP), which employs mirrors to focus the sun's heat onto a receiver. The receiver captures thermal energy that can either generate electricity immediately or store it for later use. CSP receivers increasingly use molten salt to store heat generated by the sun because it is cheap and stores thermal energy for long periods, which provides greater flexibility for the electric grid. See the Sandia National Laboratories' press release.